The Mont Alto group also provides a number of MIDI files on their site, so you can hear what these Zamecnik pieces actually sound like (as long as you still have a MIDI player). If you don’t want to mess with MIDI, here’s an .mp3 of “Mysterious – Burglar Music 1”, which I recorded off the MIDI file. (The performance in the file is copyright (P) 1998 by Rodney Sauer.)

The music is definitely a bit different from the theme we know so well, but it is undeniably a variant. I’m not entirely sure if this means this is the “patient zero” of the Villains Theme (and later versions were variants), or if Zamecnik was doing a variant from an earlier theme that also spawned the later Villains Theme, but it definitely lands very early in the Villains Theme history.

The music and the sheet music publication are in the public domain. If you want to see Zamecnik’s entire Sam Fox Moving Picture Music, Volume 1, here it is in .pdf format.

I also found a copy of the book Silent Film Sound by Rick Altman on Google Books. A discussion about Zamecnik’s silent film work and the Sam Fox music book starts on page 259. The “Mysterioso” is referenced on the following page.